Texas Gov. Rick Perry will announce today that he plans to activate up to 1,000 National Guard troops to help guard the U.S.-Mexico border, a source in the governorís office told Military Times.

It was not immediately known whether the troops will be tasked with apprehending illegal immigrants crossing the border.

In a June 11 editorial, Perry called on President Obama to send 1,000 additional troops to the Texas-Mexico border until more U.S. Border Patrol agents could be hired, trained and deployed. Perry is expected to explain on Monday why he felt the need to take action himself.

The move comes as thousands of undocumented children have streamed across the border from violence- stricken countries including El Salvador and Honduras, hoping to find asylum in the U.S.

About 2,500 undocumented children currently are being housed temporarily at three Defense Department installations: Joint Base San Antonio-Lackland, Texas; Naval Base Ventura County, California; and Fort Sill, Oklahoma.